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[ahr-suh-noh-pahy-rahyt, ahr-sen-uh-] /ˌɑr sə noʊˈpaɪ raɪt, ɑrˌsɛn ə-/
a common mineral, iron arsenic sulfide, FeAsS, occurring in silver-white to steel-gray crystals or masses: an ore of arsenic.
Also called mispickel.
1880-85; arseno- + pyrite Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for arsenopyrite
  • Metamorphism of pyrite and arsenopyrite does not increase their grain size.
  • Early pyrite or arsenopyrite as breccia filling or dissemination.
  • The gabbro may have been the heat source that concentrated the gold which is found in disseminated arsenopyrite.
British Dictionary definitions for arsenopyrite


/ˌɑːsɪnəʊˈpaɪraɪt; ɑːˌsɛnə-/
a white or grey metallic mineral consisting of a sulphide of iron and arsenic that forms monoclinic crystals with an orthorhombic shape: an ore of arsenic. Formula: FeAsS Also called mispickel
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Encyclopedia Article for arsenopyrite

an iron sulfoarsenide mineral (FeAsS), the most common ore of arsenic. It is most commonly found in ore veins that were formed at high temperatures, as at Mapimi, Mex.; Butte, Mont.; and Tunaberg, Swed. Arsenopyrite forms monoclinic or triclinic crystals with an orthorhombic shape; the physical appearance of these crystals is seldom an accurate method for determining their symmetry. A series of minerals in which cobalt partially replaces iron is called cobaltian arsenopyrites; those in which the Co:Fe ratio lies between 1:2 and 6:1 are called glaucodot (see also cobaltite). Weathering alters these sulfides to arsenates: arsenopyrite to scorodite, and glaucodot to erythrite. For detailed physical properties, see sulfide mineral (table)

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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